In general, after a radiant heat is received by a conventional temperature sensor, the temperature of a thermoelectric device therein is increased by the heat to generate a voltage signal correspondingly. Then, a data processing device in the temperature sensor correspondingly calculates a temperature data of a target object according to the voltage signal. However, a resolution of the conventional temperature sensor is unable to satisfy demands in the current industrial applications. When the target object has multiple temperature ranges, a high bit A/D converter is generally required to further increase the resolution so the temperature data of the target object with high resolution can be obtained from the voltage signal. Nonetheless, because the high bit A/D converter costs higher, the temperature sensor with high resolution will also be higher in cost.
On the other hand, in the conventional temperature sensor, the thermoelectric device provides different voltage characteristics in temperature ranges with different intervals. Such phenomenon can lead to different sensitivities of the temperature sensor in different temperature ranges and further affect an accuracy of the temperature sensor.